com.scalar.dl.ledger.statemachine

Interface Ledger<T>

All Known Implementing Classes:

DeprecatedLedger, DeprecatedLedgerTracer, JacksonBasedAssetLedger, JacksonBasedLedgerTracer, JsonpBasedAssetLedger, JsonpBasedLedgerTracer, LedgerTracerBase, StringBasedAssetLedger, StringBasedLedgerTracer

public interface Ledger<T>

A tamper-evident ledger for storing histories of Assets.

Method Summary

Modifier and Type	Method and Description
java.util.Optional<Asset<T>>	get(java.lang.String assetId) Retrieves the latest Asset entry (an asset entry with the largest age) from the ledger with the specified asset ID.
void	put(java.lang.String assetId, T data) Creates/Appends an Asset entry to the ledger.
java.util.List<Asset<T>>	scan(AssetFilter filter) Retrieves a list of Asset entries from the ledger with the specified AssetFilter.

Method Detail

get

java.util.Optional<Asset<T>> get(java.lang.String assetId)

Retrieves the latest Asset entry (an asset entry with the largest age) from the ledger with the specified asset ID.

Parameters:

assetId - an asset ID

Returns:

an Optional with the returned asset

scan

java.util.List<Asset<T>> scan(AssetFilter filter)

Retrieves a list of Asset entries from the ledger with the specified AssetFilter.

Parameters:

filter - a condition to filter asset

Returns:

a list of asset entries which passed the filtering

put

void put(java.lang.String assetId,
         T data)

Creates/Appends an Asset entry to the ledger. The initial entry is marked as age 0 and new entry is appended with an incremented age.

Parameters:

assetId - an asset ID to create/append

data - asset data